1. Technical Field of the Invention
The present invention relates to the administration of compositions containing at least one compound selected from among molecules of retinoid type for preventively or curatively treating bacterial colonizations, aggravations of pathologies or disease states caused by these colonizations and also cutaneous overinfections induced by these bacteria and, more particularly, by the bacterium Staphylococcus aureus. 
The present invention also relates to the formulation of at least one compound selected from among molecules of retinoid type into skin cleansing compositions and also to a cosmetic regime, regimen or treatment for cleansing the skin or correcting its odor, comprising topically applying such compositions onto the skin.
2. Description of the Prior Art
Compounds of retinoid type are compounds with a biological activity profile similar to that of all-trans-retinoic acid or 9-cis-retinoic acid. These compounds can modify the expression of genes by means of receptors of the retinoic acid family, such as the RARs and RXRS. Thus, retinoids may exhibit activity in the test of differentiation of mouse embryonic teratocarcinoma cells (F9) (Cancer Research, 43, p. 5268, 1983) and/or in the test of inhibition of ornithine decarboxylase after induction with TPA in mice (Cancer Research, 38, p. 793-801, 1978). These tests show the activities of these compounds in the fields of cell differentiation and cell proliferation, respectively.
Such retinoids have already been described as suited for many pharmaceutical applications, more particularly dermatological or cosmetic applications. In the pharmaceutical field, they have especially been proposed to treat dermatological, rheumatic, respiratory, cardiovascular and ophthalmological complaints, conditions or afflictions. In the dermatological or cosmetic field, EP-0,379,367, especially, discloses a method for preventively or curatively treating aged skin with retinoids.
Moreover, it is well known that the skin is covered with a flora that is responsible for an entire range of unpleasant effects ranging from the simple production of odor to more or less severe pathologies such as, for example, acne and/or dandruff.
Commensal microorganisms living on or in the skin may form part of a microflora that is either resident (normal) or transient. The resident organisms develop normally on or in the skin. Their presence is established in well-defined distribution profiles. The microorganisms that are temporarily present are referred to as transient. These microorganisms do not usually become permanently attached; they are incapable of multiplying and normally die after a few hours.
The anatomy and physiology of the skin vary from one part of the body to another and the resident microflora reflect these variations.
Most of the skin bacteria are present on the superficial squamous epidermis, colonizing the dead cells or closely associated with the sebaceous and sweat glands. Excretions from these glands provide water, amino acids, urea, electrolytes and specific fatty acids that serve as nutrient elements principally for Staphylococcus epidermidis and aerobic corynebacteria.
Gram-negative bacteria are generally present in the more humid regions. Certain pathogenic agents present on or in the skin are resident/transient and colonize the areas around orifices. Staphylococcus aureus is the best example. It is resident in the nostrils and the perianal region, but transient on the other parts of the body, where it has difficulty in surviving.
Theoretically, the epidermis is an unfavorable environment for colonization by microorganisms. Several factors, for instance periodic drying of the skin, the slightly acidic pH of the skin, the high concentration of sodium chloride in the sweat, and certain natural inhibitory substances (bactericides and/or bacteriostatic agents), are responsible for this hostile microenvironment.
The acidic pH (4-6) of the skin, due to the organic acids produced by the staphylococci and to the secretions from the sebaceous and sweat glands, discourages colonization by many microorganisms.
Sweat contains sodium chloride in a concentration that establishes hyperosmotic conditions at the surface of the skin and is an osmotic burden on many microorganisms.
Finally, certain natural inhibitory substances assist in controlling colonization, excessive growth and infection of the surface of the skin by the resident microorganisms. For example, the sweat glands excrete lysozyme which lyses Staphylococcus epidermidis and other gram-positive bacteria.
Certain gram-positive bacteria (Propionibacterium acnes) can change the lipids secreted by the sebaceous glands into unsaturated fatty acids, such as, for example, oleic acid, which exhibit strong antimicrobial activity on gram-negative bacteria and mycetes.
However, under certain conditions, this natural defense system can, although being effective, elicit unpleasant effects, or may even be neutralized.
For example, certain natural inhibitory substances (bactericides and/or bacteriostatic agents) due to the partial degradation of complex lipids secreted by the sweat glands are volatile and may be associated with a strong odor that it is customary to combat. Admittedly, many deodorants contain antibacterial substances that act selectively on the gram-positive bacteria responsible for these degradations to reduce the production of aromatic unsaturated fatty acids and body odor. However, the deodorants can modify the microflora, essentially in respect of the gram-negative bacteria, and consequently trigger infections.
Need continues to exist, therefore, in the context of treating body odor, for thus effective compounds and/or compositions that present no adverse side effects.
Another example is Propionibacterium acnes, the bacterium most commonly associated with the cutaneous glands, which is an anaerobic and lipophilic gram-positive rod. This bacterium is usually harmless. However, it has been associated with a skin disease: juvenile acne. Acne ordinarily appears during adolescence when the endocrine system is very active. The hormonal activity stimulates the overproduction of sebum, a fluid secreted by the sebaceous glands. A large volume of sebum accumulates in the glands and provides a microenvironment that is ideal for Propionibacterium acnes. In certain individuals, this accumulation triggers an inflammatory response causing redness and swelling of the glandular duct and producing a comedone, which is a plug of sebum and keratin in the canal. This results in inflammatory lesions (papules, pustules and nodules), commonly known as “blackheads”. Propionibacterium acnes appears to be the organism that produces lipases which degrade the triglycerides of the sebum into free fatty acids. These derivatives are particularly irritant since they can penetrate into the dermis and promote inflammation.
Strains of Staphylococcus aureus are known to produce toxins and superantigens, which promote the appearance of irritation reactions and of inflammatory processes. Thus, more than 90% of cases of atopic dermatitis present this bacterium (British Journal of Dermatology, 1998: 139: 13-16).
Moreover, it has been demonstrated that patients suffering from atopic dermatitis can act as reservoirs for the transmission of Staphylococcus aureus to other individuals. The studies presented in Pediatric Dermatology, Vol. 15, No. 3, 194-198, 1998 suggest that the nostrils and the hands are, respectively, major reservoirs and vectors for transmission of this bacterium to damaged skin and individuals in close contact with these patients.
It is thus important to treat these individuals suffering from atopic dermatitis, in order to prevent the aggravation of the pathology from which they are suffering, and in particular to prevent the risk of massive overinfection with Staphylococcus aureus, as is the case for “scalded skin syndrome”, but also to take preventive measures with regard to individuals who come into contact with these patients and who are liable to develop bacterial infections, in particular in a hospital environment (International Journal of Dermatology, November 1986, Vol. 25, No. 9).
An article published at pages 520 to 532 of the review entitled The New England Journal of Medicine, Vol. 339, No. 8 reflects the current state of knowledge regarding the bacterium Staphylococcus aureus, its epidemiology and the treatment of diseases in which this bacterium is involved. It will be seen from this article that the levels of colonization are thought to be higher among patients suffering from type 1 diabetes, intravenous-route drug users, blood dialysis patients, patients who have undergone surgery and patients exhibiting the human immunodeficiency syndrome. Individuals with qualitative or quantitative leukocyte defects are also thought to form part of an at-risk population with regard to colonization by the bacterium Staphylococcus aureus. 
Obviously, it has long been known to treat such afflictions, if necessary, with compounds such as antibiotics.
However, in this case also, it is known that administration of such compounds presents appreciable negative aspects. The abusive use of antibiotics may result in the emergence of resistant microorganisms on which they are no longer effective. Thus, also in this instance, need exists for effective compounds and/or compositions.
In this regard, FR-2,736,548 describes the use of a retinoid for the formulation of a bacterial medicinal product. However, the retinoids administered are aldehydes with weak antibacterial activity and which are, on account of their aldehyde function, cytotoxic and potentially allergizing.